Review article: advances in the management of patients with cirrhosis and portal hypertension-related renal dysfunction

Monitoring the fluctuation of hydrogen peroxide with a near-infrared fluorescent probe for the diagnosis and management of kidney injury

Kidney injury has become an increasing concern for patients because of environmental hazards and physiological factors. However, the early diagnosis of kidney injury remains challenging. Studies have shown that oxidative stress was closely related to the occurrence and development of kidney injury, in which abnormal hydrogen peroxide (H2O2) production was a common characteristic. Consequently, monitoring H2O2 level changes is essential for the diagnosis and management of kidney injury. Herein, based on fluorescence imaging advantages, a near-infrared fluorescent probe DHX-1 was designed to detect H2O2. DHX-1 showed high sensitivity and selectivity toward H2O2, with a fast response time and excellent imaging capacity for H2O2 in living cells and zebrafish. DHX-1 could detect H2O2 in pesticide-induced HK-2 cells, revealing the main cause of kidney injury caused by pesticides. Moreover, we performed fluorescence imaging, which confirmed H2O2 fluctuation in kidney injury caused by uric acid. In addition, DHX-1 achieved rapid screening of active compounds to ameliorate pesticide-induced kidney injury. This study presents a tool and strategy for monitoring H2O2 levels that could be employed for the early diagnosis and effective management of kidney injury.

Implication of Hypotension in the Pathogenesis of Cognitive Impairment and Brain Injury in Chronic Liver Disease

The incidence of chronic liver disease is on the rise. One of the primary causes of hospital admissions for patients with cirrhosis is hepatic encephalopathy (HE), a debilitating neurological complication. HE is defined as a reversible syndrome, yet there is growing evidence stating that, under certain conditions, HE is associated with permanent neuronal injury and irreversibility. The pathophysiology of HE primarily implicates a strong role for hyperammonemia, but it is believed other pathogenic factors are involved. The fibrotic scarring of the liver during the progression of chronic liver disease (cirrhosis) consequently leads to increased hepatic resistance and circulatory anomalies characterized by portal hypertension, hyperdynamic circulatory state and systemic hypotension. The possible repercussions of these circulatory anomalies on brain perfusion, including impaired cerebral blood flow (CBF) autoregulation, could be implicated in the development of HE and/or permanent brain injury. Furthermore, hypotensive insults incurring during gastrointestinal bleed, infection, or liver transplantation may also trigger or exacerbate brain dysfunction and cell damage. This review will focus on the role of hypotension in the onset of HE as well as in the occurrence of neuronal cell loss in cirrhosis.

Non-contrast-enhanced MR angiography of left gastric vein in patients with gastroesophageal varices: morphology and blood supply analysis

OBJECTIVES

To investigate the feasibility of non-contrast-enhanced MR angiography (NCE-MRA) in evaluating the morphology and blood supply of left gastric vein (LGV) in patients with gastroesophageal varices.

METHODS

Between March 2021 and October 2022, patients with gastroesophageal varices and who underwent NCE-MRA were retrospectively reviewed. In order to evaluate the blood supply of LGV, superior mesenteric vein (SMV) and splenic vein (SV) were visualized separately by using inflow-sensitive inversion recovery sequence. Two radiologists independently assessed the image quality, determined the origination and the blood supply of LGV, and measured the diameter of LGV. The origination and diameter of LGV were compared between NCE-MRA and contrast-enhanced CT. Differences in blood supply were compared between LGVs with different originations.

RESULTS

A total of 53 patients were enrolled in this study and the image quality was categorized as good or excellent in 52 patients. No significant differences were observed in visualizing the origination and the diameter of LGV between NCE-MRA and contrast-enhanced CT (p > .05). The blood supply of LGV was related to its origination (p < .001). Most LGVs with SV origination were supplied by SV. If LGV was originated from the portal vein (PV), about 70% of them were supplied by both SV and SMV. Compared with LGVs with SV origination, LGVs with PV origination showed more chance to receive blood from SMV (p < .001).

CONCLUSION

Non-contrast-enhanced MR angiography appears to be a reliable technique in evaluating the morphology and blood supply of LGV in patients with gastroesophageal varices.

CLINICAL RELEVANCE STATEMENT

Non-contrast-enhanced MR angiography provides valuable information for the management of gastroesophageal varices. Especially, it benefits patients with renal insufficiency.

KEY POINTS

• Non-contrast-enhanced MR angiography using inflow-sensitive inversion recovery technique can be used for evaluating not only morphology as CT but also blood supply of left gastric vein. • The blood supply of left gastric vein is related to its origination and left gastric vein with portal vein origination shows more chance to receive blood from superior mesenteric vein.

A model for predicting poor survival in patients with cirrhosis undergoing portosystemic shunt embolization

BACKGROUND AND AIM

Portosystemic shunt embolization (PSSE) is a promising treatment for hepatic encephalopathy (HEP) and gastric varix (GV) in cirrhotic patients with a spontaneous portosystemic shunt. However, PSSE may worsen portal hypertension causing hepatorenal syndrome, liver failure, and mortality. This study aimed to develop and validate a prognostic model that helps identify patients with a risk of poor short-term survival after PSSE.

METHODS

We included 188 patients who underwent PSSE for recurrent HEP or GV at a tertiary center in Korea. To develop a prediction model for 6-month survival after PSSE, Cox proportional-hazard model was used. The developed model was validated in a separate cohort of 184 patients from two other tertiary centers.

RESULTS

In multivariable analysis, the 1-year overall survival after PSSE was significantly associated with baseline levels of serum albumin, total bilirubin, and international normalized ratio (INR). We therefore developed the albumin-bilirubin-INR (ABI) score by assigning 1 point each for albumin < 3.0 g/dL, total bilirubin ≥ 1.5 mg/dL, and INR ≥ 1.5. Time-dependent areas under the curve of the ABI score for predicting 3-month and 6-month survival were 0.85 and 0.85 in the development cohort and 0.83 and 0.78 in the validation cohort, indicating good discrimination performance. The ABI score showed a better discrimination and calibration performance than the model for end-stage liver disease and the Child-Pugh scores, especially in high-risk patients.

CONCLUSIONS

The ABI score is a simple prognostic model that helps decide whether to proceed with PSSE for the prevention of HEP or GV bleeding in patients with spontaneous portosystemic shunt.

Vasopressin and Its Analogues: From Natural Hormones to Multitasking Peptides

Human neurohormone vasopressin (AVP) is synthesized in overlapping regions in the hypothalamus. It is mainly known for its vasoconstricting abilities, and it is responsible for the regulation of plasma osmolality by maintaining fluid homeostasis. Over years, many attempts have been made to modify this hormone and find AVP analogues with different pharmacological profiles that could overcome its limitations. Non-peptide AVP analogues with low molecular weight presented good affinity to AVP receptors. Natural peptide counterparts, found in animals, are successfully applied as therapeutics; for instance, lypressin used in treatment of diabetes insipidus. Synthetic peptide analogues compensate for the shortcomings of AVP. Desmopressin is more resistant to proteolysis and presents mainly antidiuretic effects, while terlipressin is a long-acting AVP analogue and a drug recommended in the treatment of varicose bleeding in patients with liver cirrhosis. Recently published results on diverse applications of AVP analogues in medicinal practice, including potential lypressin, terlipressin and ornipressin in the treatment of SARS-CoV-2, are discussed.

Research Progress and Treatment Status of Liver Cirrhosis with Hypoproteinemia

Liver cirrhosis is the 14th leading cause of death in adults worldwide. The liver is an important organ for the metabolism of sugar, protein, and fat. Liver cirrhosis with hypoproteinemia (LCH) can lead to metabolic disorders of the nutrients such as sugar, protein, and fat, as well as insufficient protein intake, digestion and absorption disorders, and continuous leakage of plasma protein into the abdominal cavity. Severe hypoproteinemia leads to a poor prognosis in patients. For every 10 g/L decrease in peripheral blood albumin, the risk of secondary liver disease complications will increase by 89% and the mortality rate increased by 24%–56%. Therefore, it is necessary to take urgent measures to treat liver cirrhosis with hypoalbuminemia and effectively treat and reverse the deterioration of the disease caused by hypoalbuminemia, so as to reduce the burden of secondary liver disease. Emerging evidence suggests that protein balance disorders, auxin resistance, and hyperleptinemia are key steps in the development of cirrhosis and hypoproteinemia. This study comprehensively analyzed the common complications, pathogenic mechanisms, and treatment status of cirrhosis caused by hypoproteinemia and proposed research prospects for dealing with this increasingly serious problem.

Does Anemia Have a Potential Effect on Type 2 Hepatorenal Syndrome?

Background/Aims. Hepatorenal syndrome (HRS) is a form of functional renal failure arising in advanced cirrhosis and is characterized by a poor survival rate. Anemia is frequently observed during the clinical course of cirrhosis. Our study aimed to investigate the hematologic findings in patients with cirrhosis to determine the effects of anemia on renal functions in type 2 HRS and if it was a potential aggravating factor. Materials and Methods. This prospective study, in which all consecutive patients with cirrhosis were enrolled, was performed at a tertiary-level hospital (Military Hospital of Tunis) from January 2019 to June 2019. A total of 9 patients with HRS fulfilled the type 2 HRS diagnostic criteria, and 41 patients with cirrhosis without HRS were included. All data regarding patients were obtained from the medical record. Demographic data, routine hemograms, biochemical, and urinary test results were collected. Models of end-stage liver disease (MELD) and Child-Turcotte-Pugh (CTP) scores were calculated. Results. The most common etiology of cirrhosis was viral hepatitis (66%). According to the CTP score, 23 patients were in the CTP-A stage, 13 in the CTP-B stage, and 14 patients were in the CTP-C stage. Patients with type 2 HRS had significantly lower hemoglobin levels compared with non-HRS stable cirrhosis patients. As hemoglobin levels decreased, renal function worsened on patients with type 2 HRS. Patients with lower hemoglobin levels had poor prognosis and survival compared with patients with higher hemoglobin levels. Logistic regression analysis showed that lower hemoglobin levels and higher MELD and CTP scores were statistically significant for an onset of type 2 HRS. Conclusion. Renal dysfunction is a frequent complication in patients with end-stage chronic liver disease. The role of anemia in aggravating HRS in patients with cirrhosis is explained by hypoxia that can lead to microcirculatory renal ischemia. Other studies are required to determine if anemia is a precipitant factor for HRS or not.

Hepatorenal Syndrome Type 1: Current Challenges And Future Prospects

Renal dysfunction represents a dreadful complication of advanced liver cirrhosis. In addition to the traditional types of acute kidney injury (AKI) that can occur in the general population, cirrhotics might experience a different kind of renal dysfunction, called hepatorenal syndrome (HRS). The exact definition of HRS is a functional renal dysfunction caused by overactivity of the endogenous vasoactive systems (in particular intrarenal circulation) which lead to reduced renal perfusion. Type I HRS (HRS-1) is characterized by an abrupt deterioration in renal function (in less than 2 weeks), defined by a doubling of baseline sCr to >2.5 mg/dL or a 50% reduction in the initial 24 hrs creatinine clearance to <20 mL/min. Frequent precipitating events leading to HRS-1 are bacterial infections, gastrointestinal hemorrhage, or large-volume paracentesis without adequate albumin administration as well as massive diuretic use. In 2015, the international club of ascites (ICA) revised the definitions and recommendations concerning HRS. The revised definition allows to adopt effective pharmacological therapy based on albumin and vasoconstrictors in an earlier stage thus not influenced anymore by a rigid sCr cut-off value as by the previous definition of HRS-1. The aim of this article was to provide an updated overview of the latest advancements in the field of hepatorenal syndrome and of the recent amendments of the previous definitions of kidney injury in cirrhotic patients.

Differential visceral blood flow in the hyperdynamic circulation of patients with liver cirrhosis

BACKGROUND

With advancing liver disease and the development of portal hypertension, there are major alterations in somatic and visceral blood flow. Using phase-contrast magnetic resonance angiography, we characterised alterations in blood flow within the hepatic, splanchnic and extra-splanchnic circulations of patients with established liver cirrhosis.

AIM

To compare blood flow in splanchnic and extra-splanchnic circulations in patients with varying degrees of cirrhosis and healthy controls.

METHODS

In a single-centre prospective study, 21 healthy volunteers and 19 patients with established liver disease (Child's stage B and C) underwent electrocardiogram-gated phase-contrast-enhanced 3T magnetic resonance angiography of the aorta, hepatic artery, portal vein, superior mesenteric artery, and the renal and common carotid arteries.

RESULTS

In comparison to healthy volunteers, resting blood flow in the descending thoracic aorta was increased by 43% in patients with liver disease (4.31 ± 1.47 vs. 3.31 ± 0.80 L/min, P = 0.011). While portal vein flow was similar (0.83 ± 0.38 vs. 0.77 ± 0.35 L/min, P = 0.649), hepatic artery flow doubled (0.50 ± 0.46 vs. 0.25 ± 0.15 L/min, P = 0.021) and consequently total liver blood flow increased by 30% (1.33 ± 0.84 vs. 1.027 ± 0.5 L/min, P = 0.043). In patients with liver disease, superior mesenteric artery flow was threefold higher (0.65 ± 0.35 vs. 0.22 ± 0.13 L/min, P < 0.001), while total renal blood flow was reduced by 40% (0.37 ± 0.14 vs. 0.62 ± 0.22 L/min, P < 0.001) and total carotid blood flow unchanged (0.62 ± 0.20 vs. 0.65 ± 0.13 L/min, P = 0.315).

CONCLUSIONS

Rather than a generalised systemic hyperdynamic circulation, liver disease is associated with dysregulated splanchnic vasodilatation and portosystemic shunting that, while inducing a high cardiac output, causes compensatory extra-splanchnic vasoconstriction - the 'splanchnic steal' phenomenon. These circulatory disturbances may underlie many of the manifestations of advanced liver disease.

Current position of vasoconstrictor and albumin infusion for type 1 hepatorenal syndrome

Spontaneous bacterial peritonitis (SBP), refractory ascites, hepatorenal syndrome (HRS), hyponatremia and hepatic encephalopathy are complications which frequently happen during a clinical course of decompensated cirrhosis. Splanchnic and peripheral vasodilatation, increased intrarenal vasoconstriction and impaired cardiac responsive function are pathological changes causing systemic and hemodynamic derangement. Extreme renal vasoconstriction leads to severe reduction of renal blood flow and glomerular filtration rate, which finally evolves into the clinical feature of HRS. Clinical manifestations of type 1 and type 2 HRS come to medical attention differently. Patients with type 1 HRS present as acute kidney injury whereas those with type 2 HRS will have refractory ascites as the leading problem. Prompt diagnosis of type 1 HRS can halt the progression of HRS to acute tubular necrosis if the combined treatment of albumin infusion and vasoconstrictors is started timely. HRS reversal was seen in 34%-60% of patients, followed with decreasing mortality. Baseline serum levels of creatinine less than 5 mg/dL, bilirubin less than 10 mg/dL, and increased mean arterial pressure of over 5 mmHg by day 3 of the combined treatment of vasoconstrictor and albumin are the predictors of good response. Type 1 HRS can be prevented in some conditions such as albumin infusion in SBP, prophylactic antibiotics for upper gastrointestinal hemorrhage, albumin replacement after large volume paracentesis in cirrhotic patients with massive ascites. The benefit of albumin infusion in infection with primary source other than SBP requires more studies.

Treatment to improve acute kidney injury in cirrhosis

OPINION STATEMENT

Acute kidney injury (AKI) is an ominous complication of decompensated cirrhosis, which can be fatal if not treated promptly. It is important that clinicians recognize that AKI has occurred and institute timely treatment. Recent establishment of diagnostic criteria and treatment guidelines are most useful, and these will be further refined as treatments are being modified to improve patient outcome. To manage such a patient, firstly, the cause of the AKI needs to be identified and any precipitating factors corrected. Bacterial infections are a common cause of AKI in cirrhosis, and it is recommended to offer empirical antibiotics in cases of suspicious bacterial infection until all the cultures are negative. Patients should be given albumin infusion in doses of 1 g/kg of body weight for at least 2 days. This can improve the filling of the central circulation, and also absorb many of the bacterial products or inflammatory cytokines that play a role in mediating the renal dysfunction. Often, albumin infusion alone may be sufficient to reverse the AKI. For patients who have acute or type 1 hepatorenal syndrome (HRS1), which is a special form of AKI, pharmacotherapy in the form of vasoconstrictor will be needed. The vasoconstrictor can be terlipressin, norepinephrine, or midodrine, depending on the local availability of drugs or facilities. Currently, approximately 40 % of patients will respond to a combination of vasoconstrictor and albumin. All patients with HRS1 should be assessed for liver transplant. If accepted for liver transplantation, those patients who do not respond to vasocontrictors and albumin need to be started on renal replacement therapy, which otherwise has no place in the treatment of HRS1. Once listed, liver transplantation should occur promptly, preferable under 2 weeks. Otherwise, the chances for renal recovery after liver transplant are significantly reduced, necessitating a renal transplant at the future date.

Renal dysfunction in cirrhosis

PURPOSE OF REVIEW

Renal dysfunction causes significant morbidity in cirrhotic patients. Diagnosis is challenging because it is based on serum creatinine, which is used to calculate estimated glomerular filtration rate, which itself is not an ideal measure of renal function in patients with cirrhosis. Finding the exact cause of renal injury in patients with cirrhosis remains problematic due to the limitations of the current diagnostic tests. The purpose of this review is to highlight studies used to diagnose renal dysfunction in patients with renal dysfunction and review current treatments.

RECENT FINDINGS

New diagnostic criteria and classification of renal dysfunction, especially for acute kidney injury (AKI), have been proposed in hopes of optimizing treatment and improving outcomes. New biomarkers that help to differentiate structural from functional AKI in cirrhotic patients have been developed, but require further investigation. Vasoconstrictors are the most commonly recommended treatment of hepatorenal syndrome (HRS). Given the high mortality in patients with type 1 HRS, all patients with HRS should be evaluated for liver transplantation. When renal dysfunction is considered irreversible, combined liver-kidney transplantation is advised.

SUMMARY

Development of new biomarkers to differentiate the different types of AKI in cirrhosis holds promise. Early intervention in cirrhotic patients with renal dysfunction offers the best hope of improving outcomes.

Hepatorenal syndrome: outcome of response to therapy and predictors of survival

Aim. Treatment of hepatorenal syndrome (HRS) in patients with liver cirrhosis is still challenging and characterized by a very high mortality. This study aimed to delineate treatment patterns and clinical outcomes of patients with HRS intravenously treated with terlipressin. Methods. In this retrospective single-center cohort study, 119 patients (median [IQR]; 56.50 [50.75–63.00] years of age) with HRS were included. All patients were treated with terlipressin and human albumin intravenously. Those with response to treatment (n = 65) were compared to the patient cohort without improvement (n = 54). Patient characteristics and clinical parameters (Child stage, ascites, hepatic encephalopathy, HRS type I/II, and initial MELD score) were retrieved. Univariate analysis of factors influencing the success of terlipressin therapy and Cox regression analysis of factors influencing survival was carried out. Results. One-month survival was significantly longer in the group of responders (p = 0.048). Cox regression analysis identified age [Hazard ratio, 95% confidence interval (CI); 1.05, 1.01–1.09, resp.], alcohol abuse [HR 3.05, 95% CI 1.11–8.38], duration of treatment [HR 0.92, 95% CI 0.88–0.96], and MELD score [HR 1.08, 95% CI 1.02–1.14] to be independent predictors of survival. Conclusions. Survival of HRS patients after treatment depends on age, etiology of liver disease, and the duration of treatment.

Role of vaptans in the management of hydroelectrolytic imbalance in liver cirrhosis

Ascites and hyponatremia are the most common complications in patients with liver cirrhosis and develop as a consequence of a severe impairment of liver function and portal hypertension. Increasing evidences support the central role of renal function alterations in the pathogenesis of hydroelectrolytic imbalances in cirrhotic patients, thus implying a dense cross-talk between liver and kidney in the systemic and splanchnic vascular homeostasis in such subjects. Since Arginin Vasopressin (AVP) hyperincretion occurs at late stage of cirrhosis and plays an important role in the development of refractory ascites, dilutional hyponatremia and finally hepato-renal syndrome, selective antagonists of AVP receptors V₂ (vaptans) have been recently introduced in the therapeutic algorithm of advanced cirrhotic patients. Despite the promising results of earlier phase-two studies, randomized controlled trials failed to find significant results in terms of efficacy of such drugs both in refractory ascites and hyponatremia. Moreover, concerns on their safety profile arise, due to the number of potentially severe side effects of vaptans in the clinical setting, such as hypernatremia, dehydration, renal impairment, and osmotic demyelination syndrome. More robust data from randomized controlled trials are needed in order to confirm the potential role of vaptans in the management of advanced cirrhotic patients.

Scoring systems for 6-month mortality in critically ill cirrhotic patients: a prospective analysis of chronic liver failure - sequential organ failure assessment score (CLIF-SOFA)

BACKGROUND

Cirrhotic patients admitted to intensive care units (ICUs) have high mortality rates. The Chronic Liver Failure-Sequential Organ Failure Assessment (CLIF-SOFA) score, a modified Sequential Organ Failure Assessment (SOFA) score, is a newly developed scoring system exclusively for patients with end-stage liver disease.

AIM

To externally validate the efficacy of the CLIF-SOFA score and evaluate other scoring systems for 6-month mortality in critically ill cirrhotic patients.

METHODS

This study prospectively recorded and analysed the data for 30 demographical parameters and some clinical characteristic variables on day 1 of 250 cirrhotic patients admitted to a 10-bed specialised hepatogastroenterology ICU in a 2000-bed tertiary care referral hospital during the period from September 2010 to August 2013.

RESULTS

The overall in-hospital and 6-month mortality rate were 58.8% (147/250) and 78.0% (195/250), respectively. Liver diseases were mostly attributed to hepatitis B virus infection (32%). Multiple Cox logistic regression hazard analysis revealed that Glasgow coma scale, both the CLIF-SOFA and Acute Physiology and Chronic Health Evaluation III (ACPACHE III) scores determined on the first day of ICU admission were independent predictors of 6-month mortality. Analysis of the area under the receiver operating characteristic curve revealed that the CLIF-SOFA score had the best discriminatory power (0.900 ± 0.020). Moreover, the cumulative 6-month survival rates differed significantly for patients with a CLIF-SOFA score ≤11 and those with a CLIF-SOFA score >11 on the ICU admission day.

CONCLUSION

Both CLIF-SOFA and APACHE III scores are excellent prognosis evaluation tools for critically ill cirrhotic patients.

Improvement in survival associated with embolisation of spontaneous portosystemic shunt in patients with recurrent hepatic encephalopathy

BACKGROUND

Spontaneous portosystemic shunt (SPSS) is a frequent cause of recurrent hepatic encephalopathy (HE) in patients with cirrhosis.

AIM

To assess the effectiveness and optimal candidate selection for embolisation of SPSS, for the treatment of recurrent HE in patients with cirrhosis.

METHODS

This retrospective cohort study compared 17 patients with recurrent HE who achieved complete occlusion of SPSS by angiographic embolisation and 17 control patients.

RESULTS

Most baseline characteristics were similar in the two groups. The 2-year HE recurrence rate was significantly lower in the embolisation than in the control group (39.9% vs. 79.9%, P = 0.02), whereas their 2-year overall survival rates were similar (64.7% vs. 53.4%, P = 0.98). Model for end-stage liver disease (MELD) and Child-Turcotte-Pugh (CTP) score were significant predictors of 2-year patient mortality in the embolisation group. Analysis of patients with MELD <15 in the absence of hepatocellular carcinoma (HCC) showed that 2-year overall survival rate was significantly higher in the embolisation group than in the control group (100% vs. 60%, P = 0.03). The median changes in MELD (-1.6 vs. 2.5, P < 0.01), CTP score (-3 vs. 0, P < 0.01), and liver volume (61 mL vs. -117 mL; P = 0.046) at 1 year significantly favoured the embolisation group. Serious clinical complications after embolisation occurred only in patients who had MELD ≥15 and/or HCC at baseline, with all six dying within 1 year.

CONCLUSIONS

Embolisation of a large spontaneous portosystemic shunt may be associated with improved survival and liver function, as well as prevention of hepatic encephalopathy in cirrhotic patients with recurrent hepatic encephalopathy and modestly preserved liver function.